The classification which dominated in Soviet linguistics some decades ago, which considered Corsican a Central Italian dialect close to Roman, Toscanian and others, is now believed as wrong. Maybe it used to be so, but nowadays the development of Corsican writing and speech apart from official Italian encourages the formation of the single Corsican language. But anyway it carries many Italian features. Besides, Corsican speech preserved much of the pre-Indo-European substratum - about 40% percent of its lexical composition in non-Romance. This substratum words are sometimes considered as close to ancient Sardian language spoken at Sardinia.